In this paper a numerical model to analyze the thermal behaviour of vertical ground heat exchangers with a helical shaped pipe is presented. This type of configuration can be a suitable alternative to conventional ground heat exchangers, especially when the heating and cooling loads of the...

This paper makes a comparative analysis between a helical-shaped pipe and a double U-tube ground heat exchanger. The two configurations were installed at a shallow depth and studied, since a depth limit is mandatory in some areas. When installed this way, the interaction between the ground...

An experimental technique is presented to non-intrusively measure the quasi-instantaneous aerodynamic loads and surrounding pressure field for a turbine by using particle image velocimetry (PIV). The PIV measurements provide the velocity flow field needed to calculate the pressure field around...

Among the non-linear loads used in household, Compact Fluorescent Lamps (CFLs) and LED lamps are becoming more widespread, while incandescent lamps are intended to be replaced by these types of lighting devices. LEDs and CFLs are significantly more efficient and economical than incandescent...

Simulations to evaluate energy demand for heating and cooling and thermal comfort are becoming more and more common place in the building design process, at least in the most complex cases. In all detailed or simplified calculations, to analyse heat transfer to and from a building, several input...

The progress met in the world market of photovoltaics underlines the maturity of investments realized, guarantees the reliability of the technology utilized and designates the variety of applications in covering the energy demands of both stand-alone and grid connected consumers. Concerning...

Maturity of the photovoltaic (PV) technology is emphasized by the numerous types of applications encountered nowadays. One of the most interesting applications, however, is the use of PV units for pumping water, i.e. the implementation of PV pumping systems (PVPSs) in order to cover both...

Across the entire Greek territory one may encounter several remote consumers that could cover their needs on the basis of PV-based stand-alone applications exploiting the high quality local solar potential. In this context, optimum sizing of such installations also involves investigation of the...

The present work investigates the effectiveness of an innovative procedure to calculate the global real sky irradiance of a mountain urban region, the city of Trento (Italy). The proposed methodology improves the predictive Bird’s real-sky model by introducing in it both atmospheric...

The photovoltaic (PV) technology has made considerable progress during the recent years in both grid connected and stand-alone applications, especially in areas of high local solar potential. In this context, the interest recently demonstrated in the Greek region concerning PVs encourages the...